介紹
SkyWalking項目是由華爲大牛吳晟開源的個人項目，目前已經加入Apache孵化器。SkyWalking項目的核心目標是針對微服務、Cloud Native、容器化架構提供應用性能監控和分佈式調用鏈追蹤功能，目前鏈路追蹤和監控應用支持的組件包括主流框架和容器，如dubbo、motan、spring boot、spring cloud等。
整體架構如下圖示：
整體主要分爲三個部分:
1.skywalking-collector：鏈路數據歸集器，數據可以保存在H2或ElasticSearch
2.skywalking-web：web的可視化管理後臺，可以查看歸集的數據
3.skywalking-agent：探針，用來收集和推送數據到歸集器
環境搭建
接下來就從零開始搭建一套skywalking環境
第一步：安裝Elasticsearch
1.下載Elasticsearch
curl -L -O https://artifacts.elastic.co/downloads/elasticsearch/elasticsearch-5.6.10.tar.gz
2.解壓壓縮包
tar -vxf elasticsearch-5.6.10.tar.gz
3.配置elasticsearch參數
cd /elasticsearch-5.6.10/config
vim elasticsearch.yml
設置參數：
cluster.name: CollectorDBCluster
node.name: CollectorDBCluster
network.host: 127.0.0.1
4.啓動ElasticSearch
./bin/elasticsearch
發現啓動失敗，提示報錯
OpenJDK 64-Bit Server VM warning: If the number of processors is expected to increase from one, then you should configure the number of parallel GC threads appropriately using -XX:ParallelGCThreads=N
OpenJDK 64-Bit Server VM warning: INFO: os::commit_memory(0x0000000085330000, 2060255232, 0) failed; error='Cannot allocate memory' (errno=12)
#
# There is insufficient memory for the Java Runtime Environment to continue.
# Native memory allocation (mmap) failed to map 2060255232 bytes for committing reserved memory.
# An error report file with more information is saved as:
# /home/elasticsearch-5.6.10/hs_err_pid1738.log
查詢資料發現是jvm內存設置問題，繼續修改參數配置。
cd config
vim jvm.options
設置參數 -Xms4g 和 -Xmx4g 將-Xms2g和-Xmx2g註釋 如下圖示
再重新啓動elasticsearch，發現再次啓動失敗，錯誤信息爲：
Exception in thread "main" java.lang.RuntimeException: don't run elasticsearch as root.
at org.elasticsearch.bootstrap.Bootstrap.initializeNatives(Bootstrap.java:93)
at org.elasticsearch.bootstrap.Bootstrap.setup(Bootstrap.java:144)
at org.elasticsearch.bootstrap.Bootstrap.init(Bootstrap.java:285)
at org.elasticsearch.bootstrap.Elasticsearch.main(Elasticsearch.java:35)
Refer to the log for complete error details.
原因是Elasticsearch是不允許使用root賬戶啓動，所以需要切換到其他用戶再啓動，最終elasticsearch啓動成功。
[2019-03-26T23:40:37,583][INFO ][o.e.n.Node ] [] initializing ... [2019-03-26T23:40:37,677][INFO ][o.e.e.NodeEnvironment ] [5DFSDCK] using [1] data paths, mounts [[/ (/dev/disk1s1)]], net usable_space [187.5gb], net total_space [233.4gb], spins? [unknown], types [apfs] [2019-03-26T23:40:37,678][INFO ][o.e.e.NodeEnvironment ] [5DFSDCK] heap size [1.9gb], compressed ordinary object pointers [true] [2019-03-26T23:40:37,679][INFO ][o.e.n.Node ] node name [5DFSDCK] derived from node ID [5DFSDCK_QhibMsJg734Ysg]; set [node.name] to override [2019-03-26T23:40:37,679][INFO ][o.e.n.Node ] version[5.6.10], pid[22167], build[b727a60/2018-06-06T15:48:34.860Z], OS[Mac OS X/10.13.6/x86_64], JVM[Oracle Corporation/Java HotSpot(TM) 64-Bit Server VM/1.8.0_191/25.191-b12] [2019-03-26T23:40:37,679][INFO ][o.e.n.Node ] JVM arguments [-Xms2g, -Xmx2g, -XX:+UseConcMarkSweepGC, -XX:CMSInitiatingOccupancyFraction=75, -XX:+UseCMSInitiatingOccupancyOnly, -XX:+AlwaysPreTouch, -Xss1m, -Djava.awt.headless=true, -Dfile.encoding=UTF-8, -Djna.nosys=true, -Djdk.io.permissionsUseCanonicalPath=true, -Dio.netty.noUnsafe=true, -Dio.netty.noKeySetOptimization=true, -Dio.netty.recycler.maxCapacityPerThread=0, -Dlog4j.shutdownHookEnabled=false, -Dlog4j2.disable.jmx=true, -Dlog4j.skipJansi=true, -XX:+HeapDumpOnOutOfMemoryError, -Des.path.home=/Users/xingwuxu/tools/elasticsearch-5.6.10] [2019-03-26T23:40:38,317][INFO ][o.e.p.PluginsService ] [5DFSDCK] loaded module [aggs-matrix-stats] [2019-03-26T23:40:38,317][INFO ][o.e.p.PluginsService ] [5DFSDCK] loaded module [ingest-common] [2019-03-26T23:40:38,317][INFO ][o.e.p.PluginsService ] [5DFSDCK] loaded module [lang-expression] [2019-03-26T23:40:38,317][INFO ][o.e.p.PluginsService ] [5DFSDCK] loaded module [lang-groovy] [2019-03-26T23:40:38,317][INFO ][o.e.p.PluginsService ] [5DFSDCK] loaded module [lang-mustache] [2019-03-26T23:40:38,317][INFO ][o.e.p.PluginsService ] [5DFSDCK] loaded module [lang-painless] [2019-03-26T23:40:38,317][INFO ][o.e.p.PluginsService ] [5DFSDCK] loaded module [parent-join] [2019-03-26T23:40:38,317][INFO ][o.e.p.PluginsService ] [5DFSDCK] loaded module [percolator] [2019-03-26T23:40:38,317][INFO ][o.e.p.PluginsService ] [5DFSDCK] loaded module [reindex] [2019-03-26T23:40:38,317][INFO ][o.e.p.PluginsService ] [5DFSDCK] loaded module [transport-netty3] [2019-03-26T23:40:38,318][INFO ][o.e.p.PluginsService ] [5DFSDCK] loaded module [transport-netty4] [2019-03-26T23:40:38,318][INFO ][o.e.p.PluginsService ] [5DFSDCK] no plugins loaded [2019-03-26T23:40:39,595][INFO ][o.e.d.DiscoveryModule ] [5DFSDCK] using discovery type [zen] [2019-03-26T23:40:39,976][INFO ][o.e.n.Node ] initialized [2019-03-26T23:40:39,976][INFO ][o.e.n.Node ] [5DFSDCK] starting ... [2019-03-26T23:40:40,167][INFO ][o.e.t.TransportService ] [5DFSDCK] publish_address {127.0.0.1:9300}, bound_addresses {[::1]:9300}, {127.0.0.1:9300} [2019-03-26T23:40:43,226][INFO ][o.e.c.s.ClusterService ] [5DFSDCK] new_master {5DFSDCK}{5DFSDCK_QhibMsJg734Ysg}{PFrWZNI9RHWNAneytiifdA}{127.0.0.1}{127.0.0.1:9300}, reason: zen-disco-elected-as-master ([0] nodes joined)[, ] [2019-03-26T23:40:43,242][INFO ][o.e.h.n.Netty4HttpServerTransport] [5DFSDCK] publish_address {127.0.0.1:9200}, bound_addresses {[::1]:9200}, {127.0.0.1:9200} [2019-03-26T23:40:43,243][INFO ][o.e.n.Node ] [5DFSDCK] started [2019-03-26T23:40:43,248][INFO ][o.e.g.GatewayService ] [5DFSDCK] recovered [0] indices into cluster_state
ElasticSearch啓動成功，監聽9200端口，此時在瀏覽器打開127.0.0.1:9200即可看到ElasticSearch的基本信息
第二步：安裝skywalking
第一步：下載skywalking
第二步：解壓壓縮包
tar -vxf -vxf
第三步：修改配置文件,將數據存儲h2配置注射，並取消es的註釋
storage: # h2: # driver: ${SW_STORAGE_H2_DRIVER:org.h2.jdbcx.JdbcDataSource} # url: ${SW_STORAGE_H2_URL:jdbc:h2:mem:skywalking-oap-db} # user: ${SW_STORAGE_H2_USER:sa} elasticsearch: # nameSpace: ${SW_NAMESPACE:""} clusterNodes: ${SW_STORAGE_ES_CLUSTER_NODES:localhost:9200} indexShardsNumber: ${SW_STORAGE_ES_INDEX_SHARDS_NUMBER:2} indexReplicasNumber: ${SW_STORAGE_ES_INDEX_REPLICAS_NUMBER:0}
第四步：啓動skywalking，執行bin目錄下的start.sh命令
./start.sh
日誌打印：
SkyWalking OAP started successfully!
SkyWalking Web Application started successfully!
skywalking啓動成功，打開瀏覽器，在瀏覽器中輸入地址localhost:8080會顯示如下界面
skywalking後臺默認登陸用戶密碼爲：admin/admin,登陸之後界面爲：
至此skywalking的基本環境搭建已完成，接下來就在實踐中看看skywalking具體都有哪些功能及具體該怎麼用？